Method and apparatus for installing electric cable systems



Dec. 5, 1950 R. P. LAPSLEY METHOD AND APPARATUS FOR INSTALLING ELECTRICCABLE SYSTEMS 4 Sheets-sheaf 1 Filed 001.. 7, 1948 INVENTOR. RHEA RLAPSLEY "III III Dec. 5, 1950 R. P. LAPSLEY 2,532,504

METHOD AND APPARATUS FOR INSTALLING ELECTRIC CABLE SYSTEMS Filed Oct. 7,1948 A-Sheets-Shaei? INVENTOR. IQHEA P. LAPSLEY A TTQQNEY Dec. 5, 1950R. P. LAPSLEY 2,532,504

METHOD AND APPARATUS FOR INSTALLING ELECTRIC CABLE SYSTEMS 4Sheets-Sheet 3 Filed Oct. 7, 1948 ATTO/PNaV Dec. 5, 1950 R P LAPSLEY2,532,

METHOD AND APPARATUS FOR INSTALLING ELECTRIC CABLE SYSTEMS 4Sheets-Sheet 4 Filed Oct. 7, 1948 ,QHEA P. LAPSLEY J V Z BY g ATTOQA/EYi l JN VEN TOR.

Patented Dec. 5, 1950 i METHOD AND APPARATUS FOR v INSTALLING ELECTRICCABLE SYSTEMS Rhea P. Lapsley, Rutherford, N. J., assignor to TheOkonite Company, Passaic, N. J., a corporation of New Jersey ApplicationOctober '1, 1948, Serial No. 53,229 16 Claims. (01.175-376) My inventionrelates to an improved method of and apparatus for installing electricpower cables into steel pipe, metallic conduit, fibre duct, cementasbestos duct or other type of raceway, either metallic or non-metallic,and magnetic or non-magnetic.

My invention is particularly adaptable to the installation of aplurality of single conductor insulated electric power cables into steelpipe as is used for high pressure so-called pipe type cable systems, andfor clarity this type of installation ivill be discussed first, andother applications ater.

In installing pipe type cable systems in accordance with conventionalpractice, a pulling wire rope is threaded through the pipe line, one endof this rope being attached to a suitable winch, and the other end to apulling eye on the end of each conductor. As the winch withdraws thepulling rope from the pipe line the conductors are drawn in. Under theseconditions the conductors assume a random position in the pipe, whichmay vary from point to point along the length of the pipe line, inasmuchas the relative position of the conductors is uncontrolled. This randomposition of conductors is known in the industry as a random lay of theconductors.

It is an object of my invention to depart from this practice in thatthroughout the drawing in of the conductors, I control the position ofthe conductors relative to each other thereby controlling the angularposition of theconductors with respect to the raceway cross sectioninstead of allowing the conductors to assume a random lay.

In an alternating current electrical cable-circuit the geometricarrangement of two or more single conductor cables installed in amagnetic steel pipe line has an effect upon the electrical properties ofthe circuit, and when the conduc tors are installed in a magnetic steelpipe line the effect of geometric arrangement is relatively large. It isdesirable that the insulated conductors be in symmetrical configurationwith respect to each other at all points throughout their length, be asclose together as practicable, and have equal and minimum proximity tothe pipe wall, if the pipe is of magnetic material. For instance, in athree phase circuit composed of three single conductor cables installedin steel pipe, the most desirable electrical characteristics areobtained whenthe conductors are twisted or spiralled together throughouttheir length. With conductors twisted or' spiralled together, thespacing'is triangular and conductors are symmetrical with respect toeach other, the outer surfaces of the cables are in contact so thecables are as close together as practicable, and the conductors haveequal and minimum proximity to the pipe wall, as the average distancefrom the bottom interior surface of the pipe wall to the conductors isincreased.

The conductors when twisted or spiralled together throughout theirlength are individually in the shape of a long helix and can thereforecontract or expand radially, without producing excessive tension orthrust on joints in the conductor when the conductor length changes dueto temperature difierences. Furthermore, when the conductors are twistedtogether, the heating of each conductor is more nearly uniform, as heatconduction along the conductors between convolutions tends to equalizetemperature along the conductor.

In the accompanying drawings wherein I have illustrated my invention asapplied to pipe type cable systems;

Figs. 1 and 2 are elevational views of one embodiment of the invention;Fig. 2 being on a slightly larger scale than Fig. 1;

Fig. 3 is a part sectional elevational view of a torque release deviceemployed in the practice of the invention;

Figs. 4 and 5 are elevational views of parts of the torque releasedevice of Fig. 3;

Fig. 6 is an enlarged elevational view of a device to be attached to thepulling line and to the conductors for guiding, spiralling, or twistingthe conductors together as they are being drawn in;

Fig. '7 is a sectional view approximately on the line 11 of Fig. 6;

Fig. 8 is a view similar to Fig. 6 of another type of conductor guidingdevice; and

Fig. 9 is a section substantially on the line 9-9 of Fig. 8.

Referring to the drawings in detail and first of all to the embodimentillustrated in Figs. 1 to 7 inclusive.

2 designates a pipe line, and 4, 6 and 8 the three separately insulatedconductors which are to be drawn thereinto. As above briefly pointedout, one object of my invention is to spiral or twist the conductorstogether as they are being drawn in, thereby positively controlling thelay of the conductors in the pipe line and avoiding the random lay whichis characteristic of this type of cable when installed by conventionalmethods.

The conductors are shipped to the installation site on separate reelsand may then be set up as illustrated more or less diagrammatically inFig. 1. As illustrated in this figure of the drawing, the reels forthese conductors are designated l0, l2 and E, respectively. In mountingthe reels, each reel is equipped with what may be termed a yoke IS. Thesides of each yoke extend across each end of the reel and are broughttogether to the rear and to the front of each reel. A shaft 58 passesthrough the two side frames of each reel yoke and through the reel toprovide for rotation of each reel on its own axis relatively to itsyoke. Where'the side frames come together at the front and rear of'thereels. I provide a sprocket 2D. The twoends of ea'ch reel yoke aremounted in stands 22 of such a height as to permit the yokes and reelsto be rotated in the stands. To provide for this rota tion, the sprocketto the rear of reel It] is belted by sprocket chain 24 to a sprocket 26mounted in a suitable stand. Then the forward end of th'e yoke'for-reelll] is belted by sprocket chain 21 to the rear end 'of the yoke for reell2, while the forward end of the yoke for reel i2 is belted by sprocketchain 2-8 to the rear end of the yoke for reel I4. It will be apparentthat this construction provides for simultaneous rotation of the threereels in their respective mountssi= multa'neously and in the samedirection by simply rotating the sprocket 2t. This has, been shown ashand driven but may be motor driven if desired. Belts and pulleys may besubstituted for the construction shown but liprefe'r the sprocket wheeland chain arrangement as this eliminates all slippage. On the otherhand, gear trains may be employed, or for that matter, the reels may notbe connected together at all but may simply Ewe-rotated in theirrespective mounts manually.

In addition to the construction to far described, the forward end ofeach reel yoke is preferably tubular or otherwise shaped or providedwith a i guide "for each conductor as it is drawn off its reel.

Between this reel set-up and the pipe line 2, I provide -a grooved idlerpulley 35 on suitable stand 32, the conductors as they pass into the opipe line passing over this pulley.

The pur ose for the reel set 'up inst described will be brought outhereinafter but I should like to note at this point that theconstruction described merely is illustrative and not definitive.

The end of each conductor is provided with a pulling eye 34 which isrigidly secured to the conductor.

The pulling rope "which is to be attached to the conductors and run over"a winch (not shown), by which the conductors are drawn into the pipeline 2, has been designated 35. This is a wire rope and its trailing endis securely attached to a swivel 38 of any suitable construction.

Attached to the pulling eyes 3 of the cable conductors is what I term atorque release device '40. The construction of this device is 'bestillustrated in Figs. 3, 4 and 5 of the drawings. This device comprises ama-le member "52, the in her end of which is threaded as shown at M andprojects loosely into female member -46.

Screwed upon the threaded end of the male member 32 and keyed thereto isa nut 18 which is a loose fit in thefemale member.

The female member at its outer end is screwtliieaded ihternallyasshown'at 5'0, andthreaded tneremto-is bushing 52. The male member 42extends through this bushing. As will be seen area Fig. 3, when thistorque release device is assembled. the inner end of the bushing '52 andouter end of the nut 48 abut each other. The abutting ends of thebushing and nut are rovided with complementary formations, illustratedas radial teeth 53, so that when tension is applied to the male andfemale members in opposed directions, the toothed faces of the bushing52 and nut 48 will be brought into Contact with each other so as to lockthe'fn and prevent relative rotation of male member 42 and female member46. Inasmuch as the outside diameter of the nut 48 is less than theinterior diameter of the female member, and inasmuch as the outsidediameter of the male member 42 is less than the interior diameter of thebushing 52, it will be apparent th'atjwithno tension on the torquerelease device thenut't and bushing 52 can move apart so thatthemale-and female members of this device may then be rotatedrelatively.

'The 0151761 end of the male member 42 of the torque release device isenlarged and bifurcated for the reception of one "end of the guiding,spiral-linger twisting "device illustrated in Figs. 6 and '7 anddesignated '54, which, as will be'eX= -plained presently is interposedbetween the torque release device 40 and the swivel '38.

The outer end of the female member 46 ofth'e torque release device isbifurcated *andequipped with p011; 5B. To attach the pulling eyes=34 ofthe conductors to the female member of the torque release device, sothat the leading ends of the conductors'are in street tied together, Iemploy short lengths =5fiof wire rope, which are threaded through thepulling eyes and are passed a'boi-It the bolt 56. The ends of these*"short lengths are secured in place by keeperolip's till.

The 'construction of the guiding, spiralling or twisting device 54 whichis interposed between the torque release device 40 and the "swivel 38,and attached to both, isb'est illustrated in 6 and '7.

From these illustrations it will be "seen that the guiding, spiralling"or twisting device comprises four angle irons 6-2, 6'4-,"56,"6'8,extending parallel toeac'h other and when the device is in use,"extending lengthwise 0f the :pipe line 2. These angle irons are so'dispo'sedreIativeIy to each other, as will be s'een'fro'm '7, as tolprovide roughly a circular cross-section. "The-angle items are s acedfrom each other, the regs 10 and 12 of angle iroh's 62 and facing eachother and providing a groove T4 *be'tweh them; the legs 1'6 and ill-ofangle irons 152 and 64 facing each other and providing a groove 8 Dbetween them;

the legs 82 and 84 of angle irons BlandSSIabing each other and providinga groove 86 between them; the legs 88 and 95 of' an'gle irons "68 and 65facing each other and providing groove "92 between them.

The 'g rooyes 1-4, 80, 86 and 92 extendlengthwise of the device and arespaced apart.

Ato'n'e e'nd of the device, the angle'irons 62 and Glare held rigidly-inspaced relation by a short spacer -94, the "same end of the angle irons66 and 68 being held 'rigi'dl'y' in spaced relation by a similarshort'spa'cer.

Bolts 9 6 pass through -the angle iron legs 16 and '10, the spacers 94and the'angle iron legs 18 and 12.

A-spacer '98 projects between the angle ironle'gs 111 and 12 and 82 and84 and 'i' riveted to these legs by rivets um. The me her ea, as will beseen hem Fig. "6, p'roji'ects beyond the ends er the angle irons for asubstantial distance so that it may be bolted to'the tail Dl" of theswivel '38.

Theguidingtwisti ng 'o'r s 'piialling 'dvic'e Stat pulling rope 36 itsopposite end is provided with similar spacers, the spacer I02 whichcorresponds to spacer 98, and the two spacers corresponding to spacers94 being offset 90 with respect to those at the other end of the device.

The spacer I02 is extended a substantial distance beyond the end of thedevice 54 for attachment to the male member 42 of the torque releasedevice.

Inserted in each of the grooves 14, 80, '85 and 92 of the device 54provided by spacing the angle irons as above described is a block H14.Each end of each block is shouldered as shown at 16 and the inner end ofeach of the spacer members is undercut as shown at N18 for cooperationwith these shoulders, so that the outward movement of the blocks I04 islimited and so that when the device is assembled, removal of the blocksis prevented.

Each block is provided in its outer face with a plurality of grooves I Iextending at an angle to the longitudinal axis of the device 54 and ofthe blocks as clearly illustrated in Fig. 6. These grooves are ofsubstantial depth. Mounted in each groove is a cutter or friction wheelI I2. The shaft H4 for each wheel H2 is set at an angle to thelongitudinal axis of its carrying block. I have shown five wheels ineach block but this number may be varied as desired as will beunderstood. 7 As will be seen from Fig. '7, the periphery of each cutteror friction wheel I I2 projects beyond the outer face of its carryingblock I94 and the blocks themselves project beyond the extremities ofthe legs of the angle irons. The blocks and wheels are urged outwardlyby springs H5, it being understood, of course, that hydraulic, pneumaticor other well known means may be employed for this purpose when desired.The device is so arranged so far as its outside dimensions areconcerned, that the wheels H2 will engage the inner face of the wall ofthe pipe line 2 with the necessary pressure when the device is in use aswill be explained later, and so that the dimensions over the angle ironswill be small enough for the device to pass minor irregularities in thepipe.

So far as the guiding, twisting or spiralling device 54 just describedis concerned, it will be appreciated that if it be inserted into a pipeline of such inside dimensions that the springs H will cause the wheelsl 42 to bite into the pipe line or be held against the pipe line underthe necessary pressure and tension is applied to the device in adirection to advance the same along the pipe, the device 54 will becaused to rotate due to the diagonal or angular setting of the wheels Il2. The distance traveled by the device 54 along the pipe for eachcomplete revolution of the device will obviously depend upon the angleat which the wheels are set, and this distance and the direction ofrotation can be varied at will by employing blocks carrying wheels setat the proper angle to give desired direction of rotation and distance.

In operation, the reels of conductors are set up at the entry end of thepipe line 2, and the threaded through the pipe line and attached to theswivel 38 at'the trailing end of the pulling rope. The swivel isattached to the leadingend of the guiding, twisting or spiralling device54. The cable conductors are drawn off their respective reels threadedthrough the guides ontheir respective yokes and led over the idlerpulley 30 and their pulling eyes 34 attached to '6 the' rearend of thetorque release device 49. The winch (not shown) to which the leading endof the pulling-rope is attached may now be started to draw the device 54through and the conductors into the pipe line. As above pointed out, thewheels I I2 either cut into the pipe line or are pressed against thepipe line with such pressure that the device 54 as it is pulled alongthe pipe will be rotated due to the angular setting of the cutter orfriction wheels l E2. The distance traveled for each revolution of thedevice 54 is predetermined. During the pulling in operation, the yokesholding the cable reels can be revolved to rotate the conductors oneturn for every complete revolution of the device 54. By observing therevolutions made by idler pulley 30, or other suitable means fordetermining the length of cable withdrawn from the reels, the operatoris constantly informed of the number of revolutions made by the device54. 1

It will be appreciated that because the device 54 rotates as it advancesthrough the pipe line, the three conductors attached thereto will beguided in a helical path and become twisted or spiralled together, asdistinguished from the uncontrolled random disposition f the conductorsin the pipe line resulting from'the conventional methods heretoforeemployed.

It will be appreciated that in the pulling-in operation, damage to thepulling rope 36 is prevented because of the provision of the swivel 38between the rear or trailing end of this rope and the guiding, twistingor spiralling device 54.

It will be appreciated also that in the pullingin operation the teeth onthe faces of the bushing 52 and nut 48 of the torque release device 46will engage as soon as tension is applied. At the end of the pull, justas the device 54 is about to emerge from the pipe line, the pullingwinch is stopped and the pulling rope slacked ofi, and the teeth of thebushing and nut of the torque release device are disengaged allowing theconductor ends to turn sufliciently to release any residual springaction of the conductors. Tension can then be reapplied and the guiding,spiralling, or twisting device pulled completely out of the pipe line,As this device leaves the pipe end, the ends of the cable conductorsemerge.

The method of installation above described will result in spirallingtogether of the conductors throughout their length, giving a lay to thecon.- ductors similar in type to that which would be obtained had thesingle conductors been spiralled together at the factory on a planetarytype cabling machine. The advantage of this "planetary typespiral-produced by use of the'reel mounting equipment shown in Fig. 1,is that the yokes holding the reels are so far as practicable rotatedone revolution for each revolution made by the guiding, twisting orspiralling device 54, and both rotations are in the same direction.Therefore, as above explained the residual twisting of individualconductors relative to the individual conductor longitudinal centralaxis is negligible as both ends of each individual conductor makeapproxmately the same number of revolutions and in the same direction.

If it is acceptable to simply twist the cables together, then themounting device shown in Fig. 1 can be omitted and the reels merelysupported on a shaft so that the reels are free to rotate as the cablesare unwound from them. Otherwise, the installation procedure would beessentially the same as described in detail above. In this type ofinstallation the cables at'their trailing *ends :are restrained by thereels-against rotation on the individual axis ot each cable while theleading ends :are moving 1a helical path, which will result in twistingtogether 01 the conductors throughout their llength, .giving a lay tothe conductorssimilar :in-type to that which would be obtained had thesingle conduc tors been twisted together at the factory on a fixedbobbin .type'cablingima'chine. With this fixed bobbin type cablingoperation, the individual conductors will be physically :d-eformedinthat the individual conductor willbe individually twisted on itsownlongitudinal "central axis one revolutionior: each revolution made by'the device MLassai-d deviceds pulled through'thepipe. Such deformationisacceptable in the cabling operationiofsmanyltypes .of cables.

I .do not profess to completely understand all the theory of just whythe twistor .'-Spira1 begins at or near the idlerpulley:3D:and'issatisfactorily uniform throughout the cable lengtnbutexperiments :I have conducted on miniature model installations haveconvinced me that satisfactory twists "or spirals-can be obtained withcable'sizes and lengths of even the largest -and longest inpresent'daynormal"commercialpractice.

Installation data indicates thatthe tension on the conductors during thepulling-in operation varies from a comparatively small force at the reelend of the .-pipe to 'a relatively large force at the winch end of thepipe. When the group -of conductor ends :is rotated bythe device 54 asit progresses @through the pipe, the individual cables :are formed :intolong helixes. These helixes tend to lengthen as "tension is increased,

- this tendency being proportional to the tension on the particularincrement of cable considered. However, as the :group of cables are incontact with each other all along their length, the helixes cannotlengthen except-by rotation of the group in-such manner as to unwind thehelixes. However, :the leading end cannot be :rotated'by this tension astheleading-end of the cable group is fixed-onto the guidingor twistingdevice54 which in turn is held'by ,penetrationcrfriction of the cutterwheels 1 1.2 into or against the pipe walls. Therefore, this tendency ofthe cable group to unwind at points of highest tens-ion :is relieved byaction of' the cable group in Winding together at :points of lowertension. this phenomenon is that as the cables are drawn into the'pipewith the leading end of the group of "cables being rotated while inmotion longitu dinally of "the pipe, the conductors twist or spiraltogether immediately after leaving the idler pulley with a length "oflay which is maintained satisfactorily uniform throughout the cablelength.

Credence is given to "the above theory when it is considered thatwith-certain types of many power transmission conductors :presentlybeing installed by conventional practice in large sizes and longlengths, there is a definite tendency .to rotation of the group ofcables at the winch end where tension is high during installation. Ofcourse, different sizes and constructions of cable exhibit thistendencyin different degrees. .Also, the pulling rope has an efiect ifit is connected to the cable group without an intervening'swivel. Theeffect of the pulling rope may be additive or subtractive on therotation "of cables. Always the rotation is insu'ch :direction as tounwind -the'most influential component of theparticula'r cable, such'asthe individual strands in compact round -=conductors, or individualsegments The net sheet 01 i would be parallel.

rsegmental conductors or the armor "of single layer wire armored cable,ia'ssuming that the 'efiect-of-the pulling rope is-small with respect tothat 'of-the' cable if the pulling 'rope effeot is subtractive to thatof the cable.

-The commercial types of single conductor cables which when installed inaccordance with conventional :practiceexhibit this tendency to a markeddegree are: (1) compact round ---con*- d-uctors, "having all strandsspiral-led in thesame direction; (2-) segmentalconductors having allstrands spiralled "in the same direction .and the segments laid "up inthe same hand as "the strands; '(3) single layer wire armored cableswhere :tension .placed *on the "armor. in a standard stranded conductor,alternate layers of strands are .spirall'ed in opposite directions, andthe tendency of each layer to untwist when-subjected to tension isofiset by that of the adjacent ilayer, so the resultant tendency cf "thecable group composed :of such cables to spiral under tension is verysmall.

-It should be noted that "when this rotation occurs near the winch endof the cables in conventional practice,the individual cables areunwound-ordeformed on their own axis one revolution for 7 everyrevolution occurring in the cable group. This action actuallyu-nakes theinsulated cables increase in length, and results in the rotated group ofconductors being longer than :the group would be had the same tensionbeen applied with the individual conductorsrestrained from rotating and"the conductor group "restrained from rotating so that the conductorsThis lengthening or deformation of the-individualstranded cables maycause some damage to the insulation of impregnated paper insulatedcables. This deformation is the same type of deformation that will occurthroughout the cable length with the fixed bobbin type of cablingoperation accomplished during installation using .my invention asexplained above, if the rotation-is in a direction to unwind theindividual strands. 'However, with my invention the rotation can be ineither direction desired. However, it should be noted that the planetarytype of cabling-operation accomplished during installation using myinvention as explained above, will eliminate this type of deformation aswell as give a satisfactory spiralled cable throughout the pipe length.This planetary type cabling can be in either direction desired.

The most satisfactory lay of the conductors appears to be obtained withplanetary type cabling in the hand opposite 'from'that of the hand ofthe individual -conductor strands. The resulting tendency of the cablegroup to untwist under tension, due to the efiect of tension tending tolengthen the cable group by'uncoil- Sing the helixes formed by theinsulated conductors, .is in opposition :to the tendency of theindividual strands to 'untwist due to tension. The preferable length oflay is such that these two opposing rotational forces balance eachother, and there is little or no tendency for-the "cable group to twisttighter or to untwist "when the tension is varied over a considerablerange. This length aof lay, or course, will vary with different cableconstructions and can be determined by tension tests on relatively shortcable samples prior to installation. The cutter wheels H2 can then "beset at the "proper angle to give this length of lay. This typebabli-ng:operation will require far less torque to be de- '9 Veloped by thedevice 54 than other types of cabling and will cause an insignificantamount of deformation to the cables during installation, in fact, farless deformation than occurs in present practice.

By another adaptation of my invention, the Single conductor cables canbe made to lay straight in the pipe without appreciable twistingtogether of the cable group at the winch end, regardless of type ofcable construction. In this case, the cutter wheels H2 of device 54 areset straight with the axis of the pipe as shown in Figs. 8 and 9, andthe device therefore follows a relatively straight path in being drawnthrough the pipe and prevents rotation of the cable group connected tothe device. This adaptation prevents the deformation of indiyidualconductors at the winch end. With this adaptation, the swivel 38 and/ortorque release device 40 can be eliminated if desired, using only thedevice 54 connected between the pulling rope and pulling eyes on thecable ends.

There is a tendency in the electric power industry to install longer andlonger lengths of power cables in order to reduce the number of jointsand manholes, and thereby effect considerable construction economy. Thistrend is occurring with both single and multi-conductor conventionalcables installed in ducts. As pulling lengths are increased, the pullingtensions go up. As the pulling tensions go up, the tendency of thecables to untwist during installation increases. In some instances ofmulticonductor lead covered cables, this tendency to untwist can becomeso great that it overcomes the ability of the cable to withstand thistendency and untwisting does occur near the winch end, causing ruptureof the lead sheath. This condition can be overcome by using the device54 connected between the pulling rope and cable ends, the cutter wheelsI I2 being set straight with the longitudinal axis of the duct, asillustrated in Figs. 8 and 9.

The basic feature of my invention is the insertion of a device betweenthe pulling rope and cables, said device having means to contact bypenetration or friction the interior surface of the raceway into whichthe cable are drawn so as to control the position of the cable endsthroughout the drawing-in operation. By such control together with theinteraction of tension and other forces mentioned above, the relativeposition of conductors with respect to each other can be controlledthroughout their length, so that a plurality of cable conductors may betwisted together as they are being drawn in, as in the embodiment of myinvention illustrated in Figs. 1 to '7, inclusive; or a plurality ofconductors may be drawn in so as to be parallel to the raceway by theuse of the device illustrated in Figs. 8 and 9; or the conductors may betwisted together before being drawn in and the device 54 of Figs. 8 and9 employed for controlling the conductors during the drawing-inoperation to prevent untwisting of the conductors in this operation.

. Of course, the type of cutter wheels used will depend to some extentupon the material of which the racewa is constructed. With some types ofraceway, it may be desirable to use wheels with fiat faces on thecircumference, or

oval faces on the circumference, and depend onfriction alone between thewheels and raceway walls, rather than wheels with sharp edges on thecircumference which do, penetrate into the raceway wall; Also, withabrasive raceways, such as cement asbestos duct or tile duct, it may bepreferable to use some form of high friction material for the wheelssuch as hard rubber.

When it is desired to follow a straight path throughout the racewayrather than a circular path, modifications can be made in the devi'ce 54to adapt it to a square or rectangular raceway.

It is to be understood that the details of construction and arrangementof parts hereinabove described and illustrated in the accompanyingdrawings may be varied within the purview of my invention.

What I claim is:

1. The method of installing a plurality of cable conductors in araceway, which method comprises continuously twisting the conductors together as they are being drawn from their respective reels and into theraceway, andsimulfl taneously rotating each conductor on its own axis inthe same hand as the said conductor twist.

2. The method of installing a plurality of cable conductors in a racewaywhich method comprises continuously guiding the leading ends of theconductors in helical paths while drawing them into the raceway,simultaneously rotating the supply reel for each conductor in the samehand as said helical paths, thereby to rotate each conductor on its ownaxis, each conductor making approximately one turn on its own axis foreach helical turn taken'by the conductors in the race-' way.

3. The method of installing a plurality of cable conductors in a racewaywhich method comprises ccntinuously guiding the leading and of theconductors in helical paths while drawing them into the raceway, andsimultaneously rotating each conductor at its trailing end on its ownaxis in the same hand as the helical paths be-- ing taken by theleadingends of the conductors,

each conductor making approximately one turn on its own axis for eachhelical turn taken by the conductors in the raceway.

4. In apparatus for installing a plurality of conductors simultaneouslyin a raceway, the com-- bination of a pulling rope, a device connectedto the pulling rope and to the leading end of the conductors, androllers carried by said device and disposed about the periphery thereof,some of said rollers constantly engaging the interior of the raceway,the rollers being set at an angle to the longitudinal axis of theraceway and en{ gaging the raceway with such pressure that as,

the conductors are being drawn into the raceway t e device and theleading end of the conductor group will rotate thereby to twist theconductors together.

5. In apparatus for installing a plurality .of'

conductors simultaneously in a raceway, the combination of a pullingrope, a device non-rotatably connected at one end to the leading end ofthe cable conductors, a swivel connection between the opposite end ofthe said device and the pulling rope and elements affixed to the devicev and disposed about its periphery, some of said.

.6.1 app ratusfo dr a. plu ality of con ductors simultaneously into a.raceway, the combination of a pulling; rope, a; conductor-guiding andtwisting device, a swivel for attaching one end of said device to: thpulling rope, a. torquereleasedevice for attaching theother endof saiddevice to the conductors and comprising cooperarble; members, one ofwhich is attached to the leadingend of the conductors and the other tothe. conductor guiding device and adapted to be drawn into non-rotatinengagement when tension is. applied to the pulling rope in a directionto, draw the conductors into the raceway, and rotatable elements afiixedto and disposed about the periphery of the conductoreguiding device andheld in engagement with the interior of the raceway, said elements beingset obliquely with respect to the longitudinal axis of the raceway: andengaging the raceway with such pressure that when tension is applied tothe pulling rope to draw the conductor-guiding devic and the; conductorsthrough the raceway the conductor guiding device will be rotated totwist the conductors together with a controlled lay.

7.. In apparatus for drawing a plurality of cone ductors simultaneouslyinto a raceway, the combination of a pulling rope, a conductor-guidingand twisting device, a swivel connection between one end of said deviceand the trailing end of the pulling rope, a torque-release, device forattaching the other end of said device to the conductors, thetorque-release device comprising two cooperating members one of which isattached to said device and the other to the leadin end of. theconductors and arranged to, be. drawn into non-rotating engagement witheach other when tension is applied to the pulling rope in a direction todraw the conductors into the raceway, and rotatable elements carried onthe periphery of the conductor-guiding device, said rotatable elementsbeing disposed obliquely to the longitudinal axis of the raceway, andmeans for maintaining the rotatable elements in contact withthe interiorof the raceway with. sufficient pressure to cause the conductor-guidingdevice and the leading end of the conductor group to rotate as theconductors are being drawn in by the. pulling rope to twist theconductors together with a controlled lay.

8. In apparatus for installing a, plurality 0.1. conductorssimultaneously in a racewaytthecombination of a supply reel for eachconductor, means for tumblingsaicl reels to rotate eachcondug flr on theaxis of the conductor, a torque-. release device comprising twocooperable members, one of which isattached tothe leadingsends of theyconductors, a conductor guidin and twist.-. ing device attached atoneend to theother member of the said torque-release device, a, swivelvconnection between the end of the conductorguiding device opposite thetorque release device and the trailing end of the pulling rope, andelements carried on the periphery of th conductorguiding device, saidelements being set obliquely relatively to the longitudinal axis of theraceway and held in constant engagement with the interior of theraceway, whereby when sufiicient tension is applied to the pulling ropeto draw the conductors into the raceway the two members of the torquerelease device will be drawn'into nonrotating engagement and theconductor-guiding device will be rotated to twist the conductorstogether with a controlled lay.

9. The method of installing a plurality of' electric cable conductors ina raceway, said method comprising drawing the conductors simultaneouslyinto a raceway while restraining the trailf2 ing end: of the;individualconductors againstrce tation on the axis of the: individualconductors and simultaneously controlling the angular posi-, tion ofthe, leading end of the individual. conductors relatively to the racewaycross sectionr 10. The method of installing a, plurality of strandedelectric cable conductors in, a raceway; said method comprisingdrawingthe conductors simultaneously'into, a, raceway, throughout thedrawing-in operation. While restrainin the trail ing end of theindividual conductorsv against rotation on the, axis of theindividualconductors, and. throughout the; drawing-in operationcontrolling the leading end of theconductors topreventrotation of thegroup due to the longitudinal tension imposed upon the conductors todraw them into the. raceway.

1 1., The methodof installing; a; pretwisted multi-conductor electriccable in a raceway, said method; comprising drawing the conductor as.-sembly into a raceway, restraining the trailing end f t nduct assemb y anstzrotation about the longitudinal axis of the conductor assembly, andcontrolling the angular relation of the leading end of the conductorassembly to the raceway cross-section throughout the drawing-inoperation, to retain the assembly substantially in its initialpretwisted condition.

12. The method of installing a plurality of cable conductors in araceway, which method comprises drawing the conductors simultaneouslyinto a raceway, restraining the trailing end of the individualconductors against rotation on the axis of the individual conductors,and moving the leadin ends of the conductors as aimit in helical pathsthroughout the drawing-in operation, continuously to twist the conductors together as they are being drawn into the raceway.

13. The method of installing a plurality of stranded single conductorcables in a raceway, which method comprises drawing the conductorssimultaneously into a raceway, restraining the trailing end of theindividual conductors against rotation on the axis of the individualconductors, and.:continuousl rotating the leading end of the conductorgroup as a unit throughout the drawing-in operation, continu-. ously to.twist the conductors. together as they are being drawn into the raceway.

14. In apparatus for installing a plurality of cable conductorssimultaneously in a raceway, the combination, of a pulling rope passingthrough the, raceway, a device, within the raceway connected at one endtothe trailing end of the, pulling rope and at its other end to theleading end of said conductors, means for applying sufiicient. tensionto the said pulling rope to, draw the conductors. simultaneously intothe raceway, and meansfor efiectingcontact of said device with the.interior surface of said raceway with sufficient pressure continuouslyto control the angular position of the leading end of the cableconductors with respect to the, raceway across-section throughout theoperation of drawing the conductors into the raceway.

15. In apparatus for installing a plurality of electric cable conductorssimultaneously ina raceway, the combination of a pulling rope passingthrough the raceway, a device within the raceway connected at one end tothe trailing end of the pulling rope and at its other end to the leadingend of said conductors, means for applying sufficient tension to thesaid pulling rope to draw the conductors simultaneousl into the raceway,means at the periphery of said device for contacting the interiorsurface of the raceway throughout the drawing of the conductors into theraceway, and means for yieldingly holding said contacting means inengagement with the interior surface of the raceway with such pressureas continuously to control the angular position of the cable conductorswith respect to the raceway cross-section throughout the operation ofdrawing the conductors into the raceway.

16. In apparatus for installing a plurality of electric cableconductors. simultaneously in a raceway, the combination of a pullingrope passing through the raceway, a device within the raceway connectedat one end to the trailing end of the pulling rope and at its other endto the leading end of said conductors, means for applying sufficienttension to the said pulling rope to draw the conductors simultaneouslyinto the raceway, guiding means carried at the pe- 14 riphery of saiddevice and engaging the interior surface of the raceway to effectrotation of the device as the device is drawn through the raceway,continuously to guide the leading end of the conductors in a rotativepath as the condwctors are being drawn into the raceway.

RHEA P. LAPSLEY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 400,958 Seely Apr. 9, 1889525,192 Dufi Aug. 28, 1894 614,597 Wrigley Nov. 22, 1898 1,177,984 BeeneApr. 4, 1916 1,732,410 Martin Oct. 22, 1929 1,933,624 Guthrie Nov. 7,1933

